Top 10 Symptoms In Dogs That You Should Never, Ever Ignore -

10. Red eye(s).

If the white area of your dog’s eye turns bright red, it indicates signs of inflammation or infection, which means one of several diseases involving the outer eyelid, third eyelid, conjunctiva, cornea, or sclera.

Redness might indicate inflammation of structures inside the eye, eye socket disorders, and glaucoma. Certain eye diseases can cause blindness, so any major changes in the appearance of the dog’s eyes should be investigated.

Some disease symptoms in dogs are better treated by merely allowing them to run their course, such as a temporary GI upset caused by indiscriminate snacking.
Other signs can be so unexpected, serious, and terrifying that you know you need to get your pet to the veterinarian or an emergency animal hospital right away.
I hope the 10 symptoms I mentioned above have given you some advice in the event that your own pet develops symptoms that point to a potentially serious or life-threatening illness.